Image file sharing method, and digital camera and center server used in image file sharing system

ABSTRACT

Group keys and image group names of image groups to which the owner of a digital camera belongs are transmitted from a server to the digital camera. The image group names are displayed in list form and an image group name is selected from the list. The group key of the selected image group is transmitted from the digital camera to the server. The server sends the digital camera access information for accessing the user computer of another user who belongs to the image group identified by the received group key. The digital camera accesses the user computer based upon the access information and receives the image file desired.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to an image file sharing method, a digital cameraused in an image file sharing system, and a center server used in such asystem.

1. Description of the Related Art

The specification of Japanese Patent Application Laid-Open No. 2003-6032describes a peer-to-peer content sharing system in which files are madeavailable among individuals in an enterprise or between enterprises sothat a one-on-one file exchange may be performed. With a peer-to-peercontent sharing system, files generally are exchanged among computerswithout the intervention of a server or the like.

A digital camera is capable of obtaining digital image data representingthe image of a subject in a comparatively simple manner by sensing theimage of the subject. However, a digital camera that is capable of filesharing the digital image data obtained and a system that includes sucha digital camera do not exist.

In addition, although there is a desire for the sharing of files only bya limited number of members, a digital camera with which such sharing ofimage files is realized also does not exist.

Also not available is a digital camera with which a shared image file,particularly a shared image file possessed by another user, can beordered for printing directly (i.e., without first downloading the fileor uploading the file to a server or the like).

DISCLOSURE OF THE INVENTION

Accordingly, an object of the present invention is to so arrange it thatan image file that has been obtained by a digital camera can bedisclosed to a group, which is composed of specific members, by usingthe digital camera.

Another object of the present invention is to so arrange it that onlyspecific members can view a disclosed image using a digital camera.

A further object of the present invention is to so arrange it that animage that is based upon a shared image file can be printed directlythrough a network using a digital camera.

Still another object of the present invention is to so arrange it thatan image that has been disclosed only to specific members can be printeddirectly through a network using a digital camera.

According to a first aspect of the present invention, the foregoingobjects are attained by providing an image file sharing methodimplemented by a digital camera and a computer possessed by each of aplurality of users, and a center server capable of data communicationwith the digital cameras and computers via a network.

The center server stores, on a per-user basis, image group informationspecifying one or a plurality of image groups to which the user belongs,and access information for accessing each computer. Further eachcomputer stores image group information specifying one or a plurality ofimage groups to which a user possessing the computer belongs. In theimage file sharing method according to the present invention, each userpossesses a digital camera and a computer. Accordingly, image groupinformation of each user stored at the center server can also bedescribed as image group information of each digital camera and computerpossessed by the user.

In upload processing for uploading the image file, the digital camerareceives the image group information specifying one or plurality ofimage groups from its own computer in the possession of the user whopossesses this digital camera, and transmits to its own computer animage file, which has been obtained by image sensing using the digitalcamera, and image group information in which the image file is to beincluded. The own computer, which has received the image file and theimage group information, stores the received image file in linkage withan image folder corresponding to the received image group information.

In download processing for downloading the image file, the digitalcamera receives from the center server the image group informationspecifying one or plurality of image groups to which the user possessingthis digital camera belongs. If an identification code (ID) specific tothe user of the digital camera (specific to the digital camera) istransmitted to the center server, then, on the basis of thisidentification code, the center server is capable of recognizing theinformation specifying one or plurality of image groups to which theuser possessing this digital camera belongs. The digital camera acceptsselection of any one item of image group information from among theimage group information received, and the image group informationselected is transmitted from the digital camera to the center server.The center server transmits, to the digital camera, access informationfor accessing other computers possessed by one or a plurality of otherusers (users other than the user possessing the above-mentioned digitalcamera) who belong to the image group specified by the image groupinformation received.

The digital camera that has received this access information transmitsthe selected image group information to another computer based upon theaccess information received. The other computer that has received theimage group information from the digital camera transmits an image file,which is linked to an image folder corresponding to the image groupinformation received, to the digital camera.

According to the first aspect of the present invention, the foregoingobjects are attained by providing a digital camera used in an image filesharing system constituted by the digital camera and a computerpossessed by each of a plurality of users, and a center server capableof data communication with the digital cameras and computers via anetwork, wherein the center server has a management information storagedevice for storing, on a per-user basis, management information thatincludes image group information specifying one or a plurality of imagegroups to which the user belongs and access information for accessingeach computer, and each computer has an image group information storagedevice for storing image group information specifying one or a pluralityof image groups to which a user possessing the computer belongs, and animage file storage device for storing an image file, which istransmitted from a digital camera, in linkage with an image foldercorresponding to image group information transmitted from the digitalcamera together with the image file. The digital camera comprises firstimage group information receiving means for receiving the image groupinformation specifying one or plurality of image groups from its owncomputer in the possession of the user who possesses this digitalcamera; image file transmitting means for transmitting an image file,which has been obtained by image sensing using the digital camera, andimage group information in which the image file is to be included, toits own computer; second image group information receiving means forreceiving from the center server the image group information specifyingone or plurality of image groups to which the user possessing thisdigital camera belongs; image group information selecting means foraccepting selection of any one item of image group information fromamong the image group information received; image group informationtransmitting means for transmitting the image group information selectedto the center server; access information receiving means for receivingaccess information, which is transmitted from the center server, foraccessing other computers possessed by one or a plurality of other userswho belong to the image group specified by the image group informationreceived; accessing means for transmitting the selected image groupinformation to another computer based upon the access informationreceived; and image file receiving means for receiving an image file,which has been linked to an image folder corresponding to the imagegroup information, transmitted from another computer that has receivedthe image group information from the digital camera.

The digital camera preferably includes a removable memory card, andmemory card control means for recording an image file, which has beenreceived by the image file receiving means, on the memory card.

In the first aspect of the present invention, the digital camera hasthree processing functions.

The first processing function is a function for sensing the image of asubject and acquiring an image file that includes digital image datarepresenting the image of the subject obtained by such image sensing.

The second processing function is a function for uploading an imagefile. In processing for uploading an image file, the digital cameracommunicates with its own computer. The digital camera's own computer isone possessed by the same owner who possesses the digital camera. Thedigital camera receives group image information to which the owner ofthe digital camera (the owner of the digital camera's own computer)belongs from its own computer and transmits the image file to beuploaded as well as the image group information in which this image fileis to be included to its own computer. The image file thus uploaded isstored in this computer in linkage with an image folder that correspondsto the image group information.

The third processing function is a function for downloading an imagefile. With the function for downloading an image file, an image filethat is transmitted from the computer of a user other than the owner ofthe digital camera (namely from another computer) is received by thedigital camera. From the center server the digital camera receives imagegroup information to-which the owner of the digital camera belongs andselects, from the image group information received, image groupinformation to which the image file to be downloaded belongs. The imagegroup information selected is transmitted to the center server. Thelatter transmits access information, which is for accessing the computerof another user (i.e., another computer) who belongs to an image groupthat is specified by the image group information received, to thedigital camera. The latter accesses the other computer based upon theaccess information received and transmits the image group informationselected. The other computer sends the accessing digital camera an imagefile that has been linked to an image folder corresponding to the imagegroup information selected.

In accordance with the first aspect of the present invention, if theowner of a digital camera and another person who is the owner of anothercomputer both belong to the same image group, an image file that hasbeen acquired by a digital camera of the this other person and stored inthe other computer can be downloaded. Image files can be exchangedbetween users belonging to the same image group.

Further, in accordance with the first aspect of the present invention,an image file that can be exchanged with another user (namely an imagefile that is disclosed) is one that has been uploaded to one's owncomputer from image files that have been acquired using a digitalcamera. If an image file that is not desired to be exchanged (disclosed)is not uploaded to one's own computer, then the image file will not bedownloaded by another user (i.e., will not be disclosed to anotheruser). Only an image file that is desired to be disclosed can bedisclosed selectively.

In an embodiment, the digital camera further includes image group namedisplay means for displaying an image group name on a display screen ofa display unit based upon one or a plurality of items of image groupinformation that have been received by the first image group informationreceiving means or second image group information receiving means. Onthe basis of an image group name that is displayed on the displayscreen, image group information in which an image file to be uploaded toone's own computer is caused to belong and image group information of animage file to be downloaded can be selected with ease.

The above-mentioned image file preferably includes original image dataand thumbnail image data. The digital camera further includes thumbnailimage data receiving means for receiving thumbnail image data in animage file, which has been linked to an image folder corresponding to animage group specified by the image group information, transmitted fromanother computer that has received image group information transmittedby the accessing means; thumbnail image display means for displaying athumbnail image represented by the thumbnail image data; desired-imageselecting means for selecting an image, for which download is desired,from thumbnail images displayed by the thumbnail image display means;and download request transmitting means for transmitting a downloadrequest to another computer having the selected image; wherein the imagefile receiving means receives an image file, for which download isdesired, transmitted from the other computer that has received thedownload request. Since an image possessed by another user can bechecked based upon a thumbnail image, an image file can be downloadedefficiently.

The first aspect of the present invention also provides theabove-described center server used in an image file sharing system. Thecenter server according this aspect of the present invention is used inan image file sharing system constituted by a digital camera and acomputer possessed by each of a plurality of users, and a center servercapable of data communication with the digital cameras and computers viaa network. The center server comprises image group information/accessinformation storage means for storing, on a per-user basis, image groupinformation specifying one or a plurality of image groups to which theuser belongs and information for accessing each of the computers; imagegroup information transmitting means for transmitting to the digitalcamera the image group information specifying one or plurality of imagegroups to which the user possessing the digital camera belongs; imagegroup information receiving means for receiving any one item of imagegroup information transmitted from a digital camera; and accessinformation transmitting means for transmitting to the digital cameraaccess information for accessing other computers possessed by one or aplurality of other users who belong to the image group specified by theimage group information received.

According to a second aspect of the present invention, the foregoingobjects are attained by providing a digital camera used in an image filesharing/printing system constituted by the digital camera and a computerpossessed by each of a plurality of users, a center server capable ofdata communication with the digital cameras and computers via a network,and a printer capable of data communication with the digital cameras andcomputers via a network, wherein the center server has a managementinformation storage device for storing, on a per-user basis, managementinformation that includes image group information specifying one or aplurality of image groups to which the user belongs and accessinformation for accessing each computer, each computer has an image filestorage device for storing an image file, which includes thumbnail imagedata and original image data, in linkage with an image foldercorresponding to one or a plurality of image groups to which a userpossessing the computer belongs, and the printer has a communicationunit which, on the basis of image specifying information and computerspecifying information transmitted from the digital camera, accesses acomputer specified by the computer specifying information and receivesan image file specified by the image specifying information transmittedfrom the computer.

The digital camera according to the second aspect of the presentinvention comprises image group information receiving means forreceiving, from the center server, the image group informationspecifying one or plurality of image groups to which the user possessingthe digital camera belongs; image group information selecting means foraccepting selection of any one item of image group information fromamong the items of image group information received; image groupinformation transmitting means for transmitting the image groupinformation selected to the center server; access information receivingmeans for receiving access information, which is transmitted from thecenter server, for accessing a computer or computers possessed by one ora plurality of other users who belong to the image group specified bythe image group information selected; accessing means for transmittingthe selected image group information to the one or plurality ofcomputers based upon the access information received; thumbnail imagedata receiving means for receiving thumbnail image data, which istransmitted from a computer that has received the image groupinformation from the digital camera, contained in an image file that hasbeen linked to an image folder corresponding to an image groupidentified by the image group information; display means for displayinga thumbnail image represented by the thumbnail image data; selectingmeans for selecting an image, which is desired to be printed, from amongthumbnail images displayed by the display means; and specifyinginformation transmitting means for transmitting, to the printer,information specifying an image to be printed selected by the selectingmeans and information specifying a computer having an image file thatrepresents the image to be printed.

A method of controlling a digital camera according to the second aspectof the present invention is for controlling a digital camera used in animage file sharing/printing system constituted by the digital camera anda computer possessed by each of a plurality of users, a center servercapable of data communication with the digital cameras and computers viaa network, and a printer capable of data communication with the digitalcameras and computers via a network, wherein the center server has amanagement information storage device for storing, on a per-user basis,management information that includes image group information specifyingone or a plurality of image groups to which the user belongs and accessinformation for accessing each computer, each computer has an image filestorage device for storing an image file, which includes thumbnail imagedata and original image data, in linkage with an image foldercorresponding to one or a plurality of image groups to which a userpossessing the computer belongs, and the printer has a communicationunit which, on the basis of image specifying information and computerspecifying information transmitted from the digital camera, accesses acomputer specified by the computer specifying information and receivesan image file specified by the image specifying information transmittedfrom the computer.

The digital camera according to the second aspect of the presentinvention is controlled so as to receive, from the center server, theimage group information specifying one or plurality of image groups towhich the user possessing the digital camera belongs; accept selectionof any one item of image group information from among the items of imagegroup information received; transmit the image group informationselected to the center server; receive access information, which istransmitted from the center server, for accessing a computer orcomputers possessed by one or a plurality of other users who belong tothe image group specified by the image group information selected;transmit the selected image group information to the one or plurality ofcomputers based upon the access information received; receive thumbnailimage data, which is transmitted from a computer that has received theimage group information from the digital camera, contained in an imagefile that has been linked to an image folder corresponding to an imagegroup identified by the image group information; display a thumbnailimage represented by the thumbnail image data received; select an image,which is desired to be printed, from among thumbnail images displayed;and transmit, to the printer, information specifying a selected image tobe printed and information specifying a computer having an image filethat represents the image to be printed.

A digital camera receives thumbnail image data transmitted from thecomputer (another computer) of another user who belongs to an imagegroup that same as that selected from one or a plurality of image groupsto which the user of the digital camera belongs. Thumbnail images basedupon this thumbnail image data are displayed on the digital camera.Information (e.g., image file names) specifying image and information(e.g., an address) specifying the other computer has been linked to thethumbnail image data. When an image to be printed is selected from thethumbnail images displayed, information (image specifying information)that specifies the selected image and information (computer specifyinginformation) specifying a computer (another computer) having the imagefile of this image is transmitted from the digital camera to theprinter.

On the basis of the image specifying information and computer specifyinginformation transmitted from the digital camera, the printer access thecomputer specified by the computer specifying information and receivesan image file specified by the image specifying information transmittedfrom the computer. The printer is capable of printing an image that isbased upon the image file possessed by the computer of the other userselected using the digital camera.

In accordance with the second aspect of the present invention, a digitalcamera can be used to order the printing of an image based upon an imagefile possessed by another user who belongs to the same image group asthat of the user of the digital camera. The image file representing theimage to be printed is transmitted to a printer from the computer havingthe image file; only the thumbnail image data is transmitted to thedigital camera. Since an image file representing an image to be printedneed not be uploaded to the server, etc., there is no major increase intraffic with regard to the network and server, etc. A desired image tobe printed can be selected (ordered for printing) in simple fashionusing the digital camera.

An image file stored in linkage with an image folder of every imagegroup stored in the image file storing device of a computer is, e.g., animage file that has been acquired by the digital camera of the user whopossesses this computer. In this case, the image file is transmittedfrom the digital camera to the computer, linked to an image foldercorresponding to a specific image group and stored in the image filestoring device of the computer. It is possible to print an image that isbased upon an image file that another user has obtained by photographyusing a digital camera.

In an embodiment, the digital camera further comprises print-numberdesignating means for designating number of prints of an image to beprinted. The specifying information transmitting means sends the printerinformation representing number of prints. Thus the printer is capableof printing out the number of desired prints of an image.

Other features and advantages of the present invention will be apparentfrom the following description taken in conjunction with theaccompanying drawings, in which like reference characters designate thesame or similar parts throughout the figures thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating the overall configuration of an imagefile sharing system;

FIG. 2 is a perspective view illustrating the back side of a digitalcamera;

FIG. 3 is a block diagram showing the overall structure of a digitalcamera;

FIG. 4 illustrates part of the content of a non-volatile memory;

FIG. 5 is a block diagram illustrating the electrical structure of auser computer;

FIG. 6 illustrates an example of a peer information database;

FIG. 7 illustrates an example of a group key/image group name managementtable;

FIG. 8A schematically illustrates a peer-to-peer folder, and FIG. 8Billustrates an example of a group key/image group name table;

FIG. 9 is a flowchart illustrating the flow of processing forregistering a new image group;

FIG. 10 is a flowchart illustrating the flow of processing forparticipation in an image group;

FIG. 11 is a flowchart illustrating the flow of processing forregistering an image file;

FIG. 12 is a flowchart illustrating the flow of processing for acquiringan image file;

FIG. 13 illustrates an example of an initial screen;

FIG. 14 illustrates an example of a network connection screen;

FIG. 15 illustrates an example of an upload screen;

FIG. 16 illustrates an example of an image group selection screen;

FIG. 17 illustrates an example of a download screen;

FIG. 18 is a diagram illustrating the overall configuration of an imagesharing/printing system;

FIG. 19 illustrates part of the content of a non-volatile memory;

FIG. 20 is a flowchart illustrating the flow of print processing;

FIG. 21 is a flowchart illustrating the flow of print processing;

FIG. 22 illustrates an example of an initial screen;

FIG. 23 illustrates an example of a selection screen; and

FIG. 24 illustrates an example of a print screen.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Preferred embodiments of the present invention will now be described indetail with reference to the accompanying drawings.

[First Embodiment]

FIG. 1 illustrates the overall configuration of an image sharing systemaccording to a first embodiment of the present invention.

The image sharing system comprises digital cameras, user computers and acenter server that are capable of being connected to a network (theInternet). The image sharing system can be made to incorporate a numberof digital cameras, a number of user computers and a single centerserver. In FIG. 1, three digital cameras 1 a to 1 c, three usercomputers 50 a to 50 c and one center server 60 are mutuallyinterconnected via the network. In the first embodiment, it is assumedthat the digital camera la and user computer 50 a are possessed by thesame owner, and that the same is true for digital camera 1 b and usercomputer 50 b and for digital camera 1 c and user computer 50 c. Thecenter server 60 is placed under the supervision of the administrator ofthe image sharing system.

With the image sharing system, an image file that has been obtained by adigital camera can be transmitted to a user computer via the network andstored on the hard disk of the user computer. Further, as will bedescribed later, a group (an image group) to which members utilizing theimage sharing system belong is formed by the image sharing system. Autilizing member who belongs to a certain image group can download animage file, which is possessed by another utilizing member who belongsto the same image group, from the user computer of this other utilizingmember using a digital camera and can view the image that is based uponthe downloaded image file using the digital camera. Conversely, if animage group is one to which a person does not belong, then the personcannot download an image file possessed by another utilizing member whobelongs to this image group.

The downloading of an image file is performed by peer-to-peercommunication in this embodiment. That is, an image file possessed byanother utilizing member who belongs to the same image group is notdownloaded from the user computer of this utilizing member via thecenter server 60, etc. Rather, the image file can be downloaded to thedigital camera through the network.

FIG. 2 is a perspective view showing the back side of the digital camera1 a. The digital cameras 1 b and 1 c also have a structure that isbasically identical with that of the digital camera 1 a. The digitalcamera 1 a will be described as representative of the digital cameras 1a to 1 c.

Provided on the top of the digital still camera 1 a is a shutter-releasebutton 3 disposed at the right-hand corner of the camera. A modeselection dial 2 is provided on the top of the digital camera 1 a at theright-hand corner. The mode selection dial 2 is for selecting a shootingmode, a play back mode and a communication mode, etc. An antenna 4 forwireless communication is provided on the top of the digital camera 1 aat the left-hand corner.

A display screen 7 of a liquid crystal display device is provided on theback side of the digital camera 1 a substantially at the center thereof.Displayed on the display screen 7 are an image captured by an imagesensing unit, an image represented by an image file that has been readout of a memory card inserted into the digital camera 1 a, and an imagefor making various settings relative to the digital camera 1 a, etc. Thedisplay screen 7 also functions as a touch-sensitive panel (input unit).

A power switch 12 is provided above the display screen 7. Provided onthe right side of the display screen 7 are an up, down, left, right key8 utilized to select a frame to be display on the display screen 7 andto make various settings, a menu button 9, an execute button 10 and acancel button 11.

FIG. 3 is a block diagram illustrating the hardware implementation ofthe digital camera 1 a.

The overall operation of the digital camera 1 a is controlled by a CPU20. A battery 43 supplies power to the CPU 20 and various other circuitsand devices included in the digital camera 1 a.

The digital camera 1 a includes a system memory 34 and a non-volatilememory 35. A program and data, etc., for controlling the operation ofthe digital camera 1 a have been stored in the system memory 34. Aprogram and data for peer-to-peer communication and other programs anddata have been stored in the non-volatile memory 35. A timer 36 is usedto measure elapsed time when photography is performed using aself-timer. Date and time are measured by a calendar and clock 37.

Output signals from the mode selection dial 2, shutter-release button 3,up, down, left, right key 8, menu button 9, execute button 10, cancelbutton 11 and power switch button 12 (assumed to be a switch 39 in FIG.3) are input to the CPU 20 via an input/output (I/O) unit 38. If thedigital camera 1 a has been provided with a light-emitting diode (LED),a light-emission signal is output to the light-emitting element via theinput/output unit 38.

An electronic flash device 5 has its light emission controlled by aflash controller 24.

If the shooting mode is selected by the mode selection dial 2, the imageof the subject is sensed by a CCD incorporated in an image sensing unit21. A video signal representing the image of the subject is output fromthe image sensing unit 21 to a signal processing circuit 22, whichproceeds to execute predetermined signal processing. The analog videosignal that has been output from the signal processing circuit 22 isconverted to digital image data in an analog/digital converting circuit23.

The digital image data is input to an LCD (Liquid Crystal display)control circuit 31 via a frame memory 29 and is converted in the LCDcontrol circuit 31 to data suited to an LCD display. Output data fromthe LCD control circuit 31 is applied to a liquid crystal display device32. An image is display on the display screen 7 included in the liquidcrystal display device 32.

Also input to the LCD control circuit 31 is an on-screen signal from anOSD (On-Screen Device) 30. Characters standing for date and timerepresented by the on-screen signal and an image representing acharacter can be displayed the display screen 7 in a form superimposedon the captured image.

As mentioned above, the display screen 7 included in the liquid crystaldisplay device 32 also functions as a touch-sensitive panel. The outputsignal from the display screen 7 is input to the CPU 20 via atouch-sensitive-panel control circuit 33.

If the shutter-release button 3 is pressed when the shooting mode hasbeen selected by the mode selection dial 2, the image data obtained asdescribed above is stored temporarily in the frame memory 29. The imagedata is read out of the frame memory 29 and is compressed by acompression/expansion circuit 25. Image data (thumbnail image data)representing an image (thumbnail image) that is a reduction of the imagerepresented by the image data is generated by the CPU 20. An image filethat contains the compressed image data, thumbnail image data, file nameand date and time of photography is created and the created image fileis recorded on the memory card 42, which has been inserted into thememory-card slot 41, via the card interface 40.

If the playback mode is selected by the mode selection dial 2, the imagefile that has been recorded on the memory card 42 is read out andapplied to the compression/expansion circuit 25 via the card interface40. The compression/expansion circuit 25 executes expansion processingand inputs the expanded image data to the LCD control circuit 31 via theframe memory 29. The image represented by the image file that has beenrecorded on the memory card 42 is displayed the display screen 7.

The digital camera 1 a is equipped with an antenna 4 for performing awireless transmission. A wireless interface 26 is connected to theantenna 4. The sending and receiving of data is performed between thedigital camera 1 a and user computer 50 a or the center server 60 viathe antenna 4. Further, the digital camera 1 a is provided with a USBinterface 27 and a connector 28 connected to the USB interface 27. Oneend of a USB cable is connected to the connector 28 and the other end ofthe USB cable is connected to the user computer 50 a. The digital camera1 a and user computer 50 a are connected by the USB cable so as to becapable of communicating.

FIG. 4 illustrates part of the content of the non-volatile memory 35with which the digital camera 1 a is equipped.

In the image sharing system, the digital camera 1 a performs datacommunication mutually with the center server 60 and with the usercomputer (the home peer) 50 a in a manner described later. Informationfor performing data communication with the center server 60 and usercomputer 50 a has been stored in the non-volatile memory 35. Thefollowing information (data) typically has been stored in thenon-volatile memory 35:

(i) Camera information: This is information for specifying the digitalcamera 1 a in the image sharing system; it includes the peer ID and theIP address of the digital camera 1 a. The peer ID has been issued(generated) by the center server 60 and is specific to the digitalcamera 1 a. The IP address is appended dynamically by the center server60 (or by another DHCP server) according to the DHCP (Dynamic HostConfiguration Protocol). The IP address may be a static IP address as amatter of course.

(ii) Center server information: This is information used to access thecenter server 60 and it includes a service ID, the peer ID of the centerserver 60, the IP address of the center server 60 and the port number ofthe center server 60.

(iii) Home peer information: This is information used to connect thedigital camera 1 a and the user computer (home peer) 50 a via thenetwork; it includes owner name, owner hash and owner ID.

(iv) Setting information for wireless LAN connection: This isinformation used to connect the digital camera 1 a to the center server60 and user computer (home peer) 50 a by radio communication. Thedigital camera 1 a is connected to the Internet by a wireless LAN andsends and receives data to and from the center server 60 and usercomputer (home peer) 50 a.

The setting information for the wireless LAN connection includes an IDfor access point connection, a key for access point connection, achannel number for access point connection, connection mode informationand setting information for IP acquisition.

FIG. 5 is a block diagram illustrating the hardware implementation ofthe user computer 50 a. The user computers 50 b and 50 c also havehardware implementations basically similar to that of the user computer50 a.

The user computer 50 a includes a CPU 51. The overall operation of theuser computer 50 a is controlled by the CPU 51. The latter is equippedwith an input unit (keyboard, mouse, etc.) 52 for inputting instructionsand commands, etc., a display unit 53 for displaying text and images,etc., a memory 54 for supplying a work area and buffer area, etc., acommunication unit 55 for sending and receiving data through thenetwork, and a hard disk 56 for storing a program and data.

Stored on the hard disk 56 of user computer 50 a in a manner similar tothat of the digital camera 1 a are information for specifying the usercomputer 50 a [the peer ID and IP address specific to the user computer50 a (the IP address may be assigned dynamically or statically)], centerserver information (the service ID, peer ID, IP address and port numberof the center server 60) and home peer information (owner name, ownerhash and owner ID). If the user computer 50 a is connectable to thenetwork by a wireless LAN, then setting information for the wireless LANconnection also is stored on the hard disk 56 of the user computer 50 ain a manner similar to that of the digital camera 1 a. Further, as willbe described later, other data for peer-to-peer communication (apeer-to-peer folder and a group key/image group name table) also isstored on the hard disk 56 of the user computer 50 a.

The center server 60 also has a hardware implementation similar to thatof the user computer 50 a described above. The hardware of the centerserver 60 is indicated within the parentheses in FIG. 5. Stored on thehard disk 66 of the center server 60 are a program and data for managingthe image sharing system (the IP address of the center server 60 as wellas the port number and other data used in the image sharing system).

A peer information database 67 and a group key/group name managementtable 68 have been stored on a hard disk 66 of the center server 60 asdata for managing the image sharing system. FIG. 6 illustrates anexample of the peer information database 67, and FIG. 7 an example ofthe group key/group name management table 68.

Information (peer information) concerning every device (user computersand digital cameras) constructing the image sharing system has beenstored in the peer information database 67 (see FIG. 6).

The peer information that has been stored in the peer informationdatabase 67 includes peer IDs, IP addresses, port numbers and group keysregarding respective ones of image groups 1, 2, 3, . . . .

Peer ID: This is an identification code that the center server 60 hasappended to each user computer and digital camera that construct theimage sharing system. The user computers and digital cameras thatconstruct the image sharing system are identified by peer IDs.

IP address: This indicates the network address of each user computer anddigital camera identified by a peer ID. If the IP address is appended byDHCP, then it is appended dynamically by the center server 60 (or byanother DHCP server) when the user computer and digital camera areconnected to the network. The IP address, therefore, is registered inthe peer information database 67. In case of a user computer or digitalcamera that employs a static IP address, the IP address is registered inthe peer information database 67.

Port number: This is a port number used in sending and receiving animage file in each user computer and digital camera and is set in eachuser computer and digital camera.

Image group: A group key for identifying an image group to which autilizing member of the image sharing system belongs is registered inthe image group section. A utilizing member can belong to one or aplurality of image groups.

In this embodiment, a utilizing member of the image sharing systempossesses a user computer and a digital camera. The same group key isregistered in the image group section of the peer information regardingthe user computer and digital camera possessed by a certain utilizingmember. That is, the group key of an image group to which a utilizingmember of the image sharing group belongs is registered in the peerinformation regarding this user computer and digital camera possessed bythe utilizing member.

The corresponding relationship between the above-described group keysand image group names is stored in the group key/group name managementtable 68 (see FIG. 7).

For example, a utilizing member who possesses a user computer having apeer ID “001” belongs to groups G001, G002 and G004, as shown in FIG. 6.A group name “Skiing” corresponds to group key “G001”, a group name“Flowers” corresponds to group key “G002”, and a group name “WeddingCeremony” corresponds to group key “G004”. Thus it will be understoodthat a utilizing member possessing a user computer of peer ID “001” isone who belongs to each of the image groups “Skiing”, “Flowers” and“Wedding Ceremony”.

FIG. 8A schematically illustrates the content of a peer-to-peer folder58 that has been stored on the hard disk 56 of a user computer (assumedto be user computer 50 a). FIG. 8B illustrates an example of a groupkey/image group name table 59 that has been stored on the hard disk 56of the user computer 50 a.

User computers 50 a to 50 c that construct the image sharing system eachhave a peer-to-peer folder 58. The latter is a folder that is accessibleby peer-to-peer communication.

The folder of every image group is linked to the peer-to-peer folder 58.Folders (referred to as “image folders” below) regarding respective onesof the image folders corresponding to the group keys “G001”, “G002”,“G004”, “G007” and “G009” are linked to the peer-to-peer folder 58 thathas been stored on the hard disk 56 of the user computer 50 a shown inFIG. 8A. Image files relating to an image group identified by a groupkey are linked to each image folder.

Image folders linked to the peer-to-peer folder 58 are provided incorrespondence with respective ones of the image groups to which theowner of the user computer belongs. As will be described later, a systemutilizing member who belongs to a certain image group can download, bypeer-to-peer communication, an image file that has been linked to animage folder of this image group in the user computer of anotherutilizing member who belongs to this image group.

Group keys regarding respective ones of the image groups to which theowner of the user computer belongs and image group names are stored inlinked form in the group key/image group name table 59 (see FIG. 8B).The five image folders whose group keys are “G001”, “G002”, “G004”,“G007” and “G009” have been linked to peer-to-peer folder 58 of the usercomputer 50 a (see FIG. 8A). That is, the owner of the user computer 50a belongs to the image groups whose group keys are “G001”, “G002”,“G004”, “G007” and “G009”. These group keys “G001”, “G002”, “G004”,“G007” and “G009” and the image group names corresponding to respectiveones of these group keys are stored in the group key/image group nametable 59 of the user computer 50 a.

(2) Operation of image sharing system

The operation of the image sharing system will now be described withreference to the flowcharts of FIGS. 9 to 12 and examples of screens onthe display screen 7 of the digital camera shown in FIGS. 13 to 17.

(I) Processing for registering new image group

FIG. 9 is a flowchart illustrating processing executed by a usercomputer and center server 60 in processing for registering a new imagegroup.

Processing for registering a new image group is processing by which autilizing member of the image sharing system creates (registers) animage group using a user computer. This will be described with regard toa case where use is made of the user computer 50 a.

Access request information is transmitted from the user computer 50 a tothe center server 60 (step 71). Information (peer ID and IP address)concerning the user computer 50 a and center server information (serviceID, peer ID, IP address and port number) has been stored on the harddisk 56 of the user computer 50 a in the manner described above. Theaccess request information is transmitted from the user computer 50 a tothe center server 60 based upon the center server information. Further,the access request information contains information (peer ID and IPaddress) concerning the user computer 50 a.

On the basis of the information (peer ID) concerning the user computer50 a contained in the access request information, the center server 60that has received the access request information refers to the peerinformation database 67 (FIG. 6) to determine whether the user computer50 a is a computer constituting the image sharing system (i.e., whetherthe user of the user computer 50 a is a utilizing member of the imagesharing system). Since the user computer 50 a is one constituting theimage sharing system (i.e., since the peer ID contained in the accessrequest information has been registered in the peer information database67), the center server 60 enables the connection of the user computer 50a and sends the user computer 50 a data indicating that the connectionhas been completed (step 72).

Upon receiving the data indicating completion of connection from thecenter server 60, the user computer 50 a executes processing forcreating a new image group (step 73). In processing for creating a newimage group, the user of the user computer 50 a uses the input unit 52to input the name of the image group to be created anew. New-groupregistration request information that contains the entered image groupname is transmitted from the user computer 50 a to the center server 60(step 74).

Upon receiving the new-group registration request information, thecenter server 60 creates a group key. The created group key isregistered in the image group section of the peer information in thepeer information database 67 regarding the user computer 50 a identifiedby the peer ID received from the user computer 50 a beforehand.Furthermore, the center server 60 also registers the created group keyin the image group section of the peer information in the peerinformation database 67 regarding the digital camera 1 a possessed bythe owner of the user computer 50 a. (This is a case where the centerserver 60 has grasped the corresponding relationship between the peerIDs of the user computer and digital camera possessed by the same owner.Of course, the peer ID of the digital camera 1 a may be included in theaccess request information together with the peer ID of the usercomputer 50 a and the created group key may be registered in the peerinformation regarding the user computer 50 a and digital camera 1 apossessed by the same owner based upon these two peer IDs.) The createdgroup key and the image group name contained in the received new-groupregistration request information are registered in correspondence witheach other in the group key/group name management table 68 (see FIG. 7)(step 75).

The center server 60 transmits the created group key to the usercomputer 50 a (step 76). The latter registers the received group key andthe entered image group name in the group key/image group name table 59(FIG. 8B) (step 77). Processing for registering the new image group thenends.

It may be so arranged that a group key created at the center server 60and transmitted to the user computer 50 a is transmitted upon beingencrypted. In this case, the encrypted group key is decoded at the usercomputer 50 a and registered in the group key/image group name table 59.

It goes without saying that in a case where a new image group has beencreated using the user computer 50 a, an image folder corresponding tothe newly created image group is created in the peer-to-peer folder 58(FIG. 8A) of the user computer 50 a.

(II) Processing for participation in an image group

FIG. 10 is a flowchart illustrating the flows of processing executed bya user computer and center server 60 for participation in an imagegroup.

Processing for participation in an image group is processing executed ina case where a utilizing member of the image sharing system participatesin an image group created by the above-described processing (FIG. 9) forregistering a new image group. This will be described with regard to acase where use is made of the user computer 50 a.

A utilizing member who wishes to participate in an image group acceptsas by e-mail the group key of the image group in which participation isdesired from the utilizing member who created the image group (step 81).Of course, the group key may be accepted from another utilizing memberwho received the group key from the utilizing member who created theimage group.

The group key accepted as by e-mail is registered in the group key/imagegroup name table 59 (FIG. 8B) at the user computer 50 a (step 82).

Access request information is transmitted from the user computer 50 a tothe center server 60 (step 83). Upon allowing access, the center server60 transmits the fact that access has been achieved to the user computer50 a (step 84).

The user computer 50 a sends the center server 60 information requestingregistration of the desired participation group (step 85). Thisinformation requesting registration of the desired participation groupincludes the group key of the image group in which participation isdesired, the group key having been received as by e-mail and registeredin the group key/image group name table 59 in advance in the mannerdescribed above.

Upon receiving the information requesting registration of the desiredparticipation group, the center server 60 registers the group key, whichis contained in the information requesting registration of the desiredparticipation group, in the image group section of the peer informationregarding the user computer 50 a and digital camera 1 a in the peerinformation database 67 (step 86). Further, the center server 60 refersto the group key/group name management table 68 and sends the usercomputer 50 a the image group name corresponding to the registered groupkey (step 87).

The user computer 50 a stores the received image group name in the groupkey/image group name table 59 in a form linked to the group key (step88). This ends the processing for participating in an image group.

As a result of the above-described processing for registering a newimage group (FIG. 9) and processing for participating in an image group(FIG. 10), the group key of an image group in which a utilizing memberof the image sharing system is participating is registered in the peerinformation concerning the user computer and digital camera possessed bythe utilizing member of the image sharing system. One or a plurality ofimage groups in which each utilizing member of the image sharing systemis participating is (are) registered at the center server 60. Thecorresponding relationship between group keys and image group namesregarding all image groups created in the image sharing system isregistered in the group key/group name management table 68. Thecorresponding relationship between group keys and image group namesregarding image groups in which the user of each user computer isparticipating is registered at each user computer.

(III) Processing for registering an image file (upload processing)

FIG. 11 is a flowchart illustrating the flows of processing executed bya digital camera and user computer for registering an image file. FIGS.13 to 15 illustrate examples of screens displayed on the display screen7 of a digital camera in this processing for registering an image file.

Processing for registering an image file is processing whereby autilizing member of the image sharing system takes a picture of asubject using a digital camera and stores an image file, which has beenrecorded on the memory card 42 as a result, on the hard disk of the usercomputer possessed by this utilizing member. This will be described withregard to a case where use is made of the digital camera 1 a and usercomputer 50 a.

If the communication mode is selected using the mode selection dial 2 ofthe digital camera 1 a, an initial screen W1 is displayed the displayscreen 7 of the digital camera 1 a, as illustrated in FIG. 13.

The initial screen W1 includes three selectable areas, namely “UPLOAD”W1 a, “VIEW” W1 b and “BACK” W1 a. Any one of “UPLOAD” W1 a, “VIEW” W1 band “BACK” W1 a can be selected by operating the up, down, left, rightkey 8 or by touching the display screen 7. “UPLOAD” W1 a is selected inimage file registration processing.

If “UPLOAD” W1 a is selected, a network connection screen W2 (see FIG.14) instead of the initial screen W1 appears on the display screen 7.The network connection screen W2 includes an “OK” button W2 a and a“BACK” button W2 b. If the “OK” button W2 a is selected, a transition ismade to the processing described next. If the “BACK” button W2 b ispressed, the initial screen W1 is displayed the display screen 7 again.

As mentioned above, information (home peer information) necessary fordata communication with the user computer 50 a (home peer) has beenstored in the non-volatile memory 35 (FIG. 4) of the digital camera 1 a.Access request information is transmitted from the digital camera 1 a tothe user computer 50 a based upon the home peer information via anetwork (step 91). The access request information transmitted from thedigital camera 1 a to the user computer 50 a includes camera information(peer ID and IP address) that has been stored in the non-volatile memory35.

Upon receiving the access request information from the digital camera 1a, the user computer 50 a sends the digital camera 1 a data representingthe fact that access has been achieved (step 92).

Information requesting image group names is transmitted from the digitalcamera 1 a to the user computer 50 a (step 93). Upon receiving theinformation requesting image group names, the user computer 50 a sendsthe digital camera 1 a the sets of all group keys and image group namesthat have been stored in the group key/image group name table 59 (step94).

The group keys and image group names are stored temporarily in thenon-volatile memory 35 of the digital camera 1 a.

An upload screen W3 (see FIG. 15) is displayed the display screen 7 ofthe digital camera 1 a (step 95).

The upload screen W3 includes an image group name display area W3 a andan image display area W3 b. Image group names that have been transmittedfrom the user computer 50 a are displayed in the image group namedisplay area 3 a in list form. The image group names displayed in theimage group name display area W3 a are based upon the image group namesthat have been stored in the non-volatile memory 35. Thumbnail imagesbased upon the image files that have been recorded on the memory card 42are displayed in the image display area W3 b.

The user of the user computer 50 a selects the image desired to beuploaded from among the thumbnail images being displayed in the imagedisplay area W3 b and selects the group name of the image group in whichthe selected image is to be included from among the image group namesbeing displayed in the image group name display area W3 a (steps 96,97). If a plurality of images are to be uploaded, the selection of theimage and the selection of the image group name are repeated.

If the execute button 10 is pressed, the image file representing theselected image is read out of the memory card 42 and the group key ofthe selected image group is read out of the non-volatile memory 35. Theimage file and the group key are linked and transmitted from the digitalcamera 1 a to the user computer 50 a (step 98).

Upon receiving the image file and the group key, the user computer 50 astores the received image file in linkage with the image folder insidethe peer-to-peer folder 58 (see FIG. 8A) identified by the group key(step 99). This ends the processing for registering an image file.

(IV) Image file acquisition processing (view mode processing)

FIG. 12 is a flowchart illustrating the flows of processing executed bya digital camera, center server and user computer for acquiring an imagefile, and FIGS. 16 and 17 illustrate examples of screens displayed thedisplay screen 7 of the digital camera in image file acquisitionprocessing.

Image file acquisition processing is processing by which a utilizingmember acquires the image of another utilizing member who belongs to animage group that is the same as that to which the first-mentionedutilizing member belongs. This will be described with regard to a casewhere use is made of the digital camera 1 a and user computer 50 a.

When “VIEW” W1 b is selected on the initial screen W1 (FIG. 13) and the“OK” button W2 a is selected on the network connection screen W2 (FIG.14), a transition is made to the processing described below.

Access request information is transmitted from the digital camera 1 a tothe center server 60 via the network (step 101). Center serverinformation that has been stored in the non-volatile memory 35 of thedigital camera 1 a is used to transmit the access request informationfrom the digital camera 1 a to the non-volatile memory 35. The accessrequest information includes information (peer ID and ID address)concerning the digital camera 1 a.

In a manner similar to that of the case where processing for registeringa new image group is executed, it is determined based upon information(peer ID) concerning the digital camera 1 a whether the digital camera 1a is one constituting the image sharing system. Data indicating the factthat access has been achieved is transmitted from the center server 60to the digital camera 1 a, which is one constituting the image sharingsystem (step 102).

Request information requesting image group names is transmitted from thedigital camera 1 a to the center server 60 (step 103). Upon receivingthis request information, the center server 60 refers to the peerinformation database 67 based upon the peer ID transmitted from thedigital camera 1 a, reads out the group keys of the image groups towhich the owner of the digital camera 1 a (the owner of the usercomputer 50 a) belongs, reads the image group names that correspond tothese group keys out of the group key/group name management table 68 andtransmits the group keys and the image group names to the digital camera1 a (step 104). The group keys and the image group names are stored inthe non-volatile memory 35 of the digital camera 1 a.

An image group selection screen W4 shown in FIG. 16 is displayed thedisplay screen 7 of the digital camera 1. The image group selectionscreen W4 includes an image group name display area W4 a, in which theimage group names that have been stored in the non-volatile memory 35are display (step 105).

By operating the up, down, left, right key 8 or touching the displayscreen 7, the user of the digital camera 1 a selects the image groupname of the image group from which acquisition of an image is desiredfrom among the image group names being displayed in the image group namedisplay area W4 b (step 106). The group key regarding the selected imagegroup is read out of the non-volatile memory 35 and transmitted to thecenter server 60 (step 107).

Upon receiving the group key, the center server 60 goes to the peerinformation database 67 and reads out access information (peer IDs, IPaddresses and port numbers) for accessing the user computers of theutilizing members belonging to the image group specified by the groupkey received (step 108). The access information read out is transmittedfrom the center server 60 to the digital camera 1 a (step 109). Itshould be noted that if user computers are connected to a network andthe IP addresses appended by the DHCP, then an IP address will not havebeen registered in peer information regarding a user computer that hasnot been connected to the network. It goes without saying that accessinformation regarding such a user computer is not transmitted to thedigital camera 1 a. Further, it may be so arranged that the centerserver 60 accesses the user computer beforehand based upon accessinformation read out, queries the user computer as to whether it is inan accessible state and, as a result of the query, sends the digitalcamera 1 a only access information regarding a user computer that isaccessible.

Upon receiving access information from the center server 60, the digitalcamera 1 a, based upon the received access information, transmits accessrequest information, which is for requesting thumbnail image data, tothe user computers specified by the access information (step 110). Ofcourse, this acquisition request information also contains the group keyregarding the selected image group and camera information (peer ID andIP address) regarding the digital camera 1 a.

Upon receiving the information transmitted from the digital camera 1 afor the purpose of requesting acquisition of thumbnail image data, theuser computer, based upon the group key contained in the acquisitionrequest information, reads out thumbnail image data contained in theimage files linked to the image folder regarding the image groupidentified by this group key, links its own IP address with thethumbnail image data and transmits the thumbnail image data to thedigital camera 1 a (step 111). If the digital camera 1 a has receivedmultiple items of access information from the center server 60, then theabove-mentioned information for requesting acquisition of thumbnailimage data is transmitted by the digital camera 1 a to a plurality ofuser computers. In this case each of the plurality of user computerssends the digital camera 1 a a set of data that includes the images(thumbnail image data) regarding the selected image group and the IPaddress.

Thumbnail images that are based upon the received thumbnail image dataare displayed in an image display area W5 b on the display screen 7 ofthe digital camera 1 a (step 112; see download screen W5 in FIG. 17).

The owner of the digital camera 1 a selects one or a plurality of imagesdesired for downloading from among the thumbnail images being displayedin the image display area W5 b (step 113). On the basis of the IPaddress that has been linked to the selected thumbnail image, downloadrequest information is transmitted to the user computer having the imagefile representing the selected thumbnail image (step 114). The downloadrequest information includes the image file name (contained in thethumbnail image data) for which download is requested.

Upon receiving the download request information, the user computertransmits the requested image file to the digital camera 1 a (step 115).The image file transmitted from the user computer is recorded on thememory card 42 of the digital camera 1 a (step 116).

[Second Embodiment]

FIG. 18 is a diagram illustrating the overall configuration of an imagesharing/printing system.

The image sharing/printing system comprises digital cameras, usercomputers, a center server and a printer that are capable of beingconnected to a network (the Internet). The image sharing/printing systemcan be made to incorporate a number of digital cameras, a number of usercomputers, a plurality of printers and a single center server. In FIG.18, three digital cameras 1 a to 1 a, three user computers 50 a to 50 c,one center server 60 and one printer 70 are mutually interconnected viathe network. This system differs from the image sharing system of thefirst embodiment (FIG. 1) in that the printer 70 has been connected tothe network. In the description that follows, components identical withthose of the first embodiment are designated by like referencecharacters and need not be described again.

With this image sharing/printing system, an image based upon an imagefile that has been recorded on a memory card inserted into a digitalcamera and an image file (stored in a user computer) that belongs toanother utilizing member who belongs to the same image group can beprinted from the printer 70 through use of the digital camera. Thisfunction is in addition to the functions of the image sharing systemaccording to the first embodiment.

FIG. 19 illustrates part of the content of the non-volatile memory 35with which the digital camera 1 a is equipped. This content differs fromthat of the non-volatile memory 35 (FIG. 4) in the digital camera 1 a ofthe first embodiment in that printer peer information has been addedthereto.

Printer peer information is information used to connect the digitalcamera 1 a and printer 70 via the network and it includes the peer ID ofthe printer 70, the IP address of the printer 70 and port number of theprinter 70. The printer peer information is stored also on the hard diskof the user computer.

As in the first embodiment, processing (FIG. 9) for registering a newimage group, processing (FIG. 10) for participating in an image group,processing (FIG. 11) for registering an image file and processing (FIG.12) for acquiring an image file can be executed in the imagesharing/printing system of the second embodiment as well. In addition tothe above processing, print processing also can be executed in the imagesharing/printing system of the second embodiment.

FIG. 20 is a flowchart illustrating the flows of processing executed bya digital camera and printer in print processing.

Print processing is processing whereby the owner of a digital cameracauses the printer 70 to print an image that is based upon an image filethat has been recorded on the memory card 42. This will be describedwith regard to a case where use is made of the digital camera 1 a.

If the communication mode is selected using the mode selection dial 2 ofthe digital camera 1 a, an initial screen W1A (see FIG. 22) is displayedthe display screen 7. This screen differs from the initial screen W1(FIG. 13) of the first embodiment in that a “PRINT” selection area,indicated at W1 a, has been added thereto.

If “PRINT” W1 a is selected, a selection screen W6 illustrated in FIG.23 is displayed. The selection screen W6 is a screen for selectingwhether to print an image that is based upon an image file that has beenrecorded on the memory card 42 inserted into the digital camera 1 a oran image that is based upon an image file (stored in the user computerof another utilizing member) possessed by the other utilizing member. If“PRINT OWN IMAGE” W6 a is selected, control proceeds to print processing(part 1) shown in FIG. 20.

Access request information is transmitted from the digital camera 1 a tothe printer 70 via the network (step 121). Printer peer information thathas been stored in the non-volatile memory 35 of the digital camera 1 ais used to transmit this access request information. The access requestinformation includes information (peer ID and IP address) concerning thedigital camera 1 a. The printer 70 sends the digital camera 1 ainformation indicating that access has been achieved (step 122).

Images (which are based upon either original image data or thumbnailimage data) based upon image files that have been recorded on the memorycard 42 are displayed the display screen 7 of the digital camera 1 a(step 123; no associated drawing shown).

An image desired to be printed is selected from among the images display(step 124). Print request information (print ordering information) istransmitted from the digital camera 1 a to the printer 70 (step 125).The print request information can be made to incorporate the selectedimage file, an indication as to how many prints (the number of prints)are to be made of the image that is based upon the selected image file,and other information.

In a case where images based upon image files of multiple types areprinted, selection of the image and transmission of the print requestinformation are repeated. (It should be noted that even a singletransmission of the print request information will suffice.) Uponreceiving the print request information transmitted from the digitalcamera 1 a, the printer 70 prints the image, which is represented by theimage file contained in the print request information, based upon theprint request information received (step 126).

If quit information is transmitted from the digital camera 1 a to theprinter 70 (e.g., the quit information is transmitted if the modeselection dial 2 is changed over from the communication mode to anothermode) (step 127), the printer 70 transmits quit completion informationto the digital camera 1 a (step 128). Print processing ends as a result.

The owner of the digital camera 1 a would go to the place (a photo lab,etc.) of installation of the printer 70 at a later date to pick up theprints that have been output by the printer 70.

FIG. 21 is a flowchart illustrating the flows of processing executed bya digital camera, printer and user computer in print processing. Theflowchart of print processing shown in FIG. 21 represents a continuationof processing similar to the processing up to step 112 of the flowchartof processing for acquiring an image file shown in FIG. 12 of the firstembodiment. That is, in print processing (part 2) shown in FIG. 21, theprocessing executed is similar to the processing up to display (step112) of a thumbnail image of a selected group in image file acquisitionprocessing illustrated in FIG. 12.

Print processing is processing whereby the owner of a digital camerauses the printer 70 to print an image that is based upon an image filepossessed by another utilizing member. When “PRINT OTHER PERSON'S IMAGE”W6 b is selected on the selection screen W6 shown in FIG. 23, an accessrequest is transmitted from the digital camera 1 a to the printer 70(step 131) and information indicating achievement of access istransmitted from the printer 70 to the digital camera 1 a (step 132). Aprint screen W7 (see FIG. 24) is displayed the display screen 7.

The owner of the digital camera 1 a selects one or a plurality ofthumbnail images desired to be printed from among thumbnail images beingdisplayed an image display area W7 b on the print screen W7 (step 133).

Print request information (print ordering information) relating to theselected thumbnail image is transmitted from the digital camera 1 a tothe printer 70 (step 134). The print request information includes the IPaddress that has been linked to the selected thumbnail image (the IPaddress of the user computer storing the image file that contains thedata representing the selected thumbnail image) and the image file name.Of course, data representing the number of prints and other data may beincorporated in the print request information.

Upon receiving the print request information from the digital camera 1a, the printer 70, based upon the IP address included in the printrequest information received, transmits download request information tothe user computer having the image file of the image file name containedin the print request information (step 135). Upon receiving the downloadrequest information, the user computer reads the request image file outof the hard disk 56 and transmits the image file to the printer 70 (step136). The image that is based upon the received image file is printed bythe printer 70 (step 137).

If quit information is transmitted from the digital camera 1 a to theprinter 70 (step 138), then the printer 70 transmits quit completioninformation to the digital camera 1 a (step 139). Print processing endsas a result.

As many apparently widely different embodiments of the present inventioncan be made without departing from the spirit and scope thereof, it isto be understood that the invention is not limited to the specificembodiments thereof except as defined in the appended claims.

1. An image file sharing method implemented by digital cameras andcomputers possessed by each of a plurality of users, and a center servercapable of data communication with the digital cameras and computers viaa network, said method comprising the steps of: said center serverstoring, on a per-user basis, image group information specifying one ora plurality of image groups to which the user belongs, and accessinformation for accessing each computer; each computer storing imagegroup information specifying one or a plurality of image groups to whichthe user possessing said computer belongs; in upload processing foruploading an image file, said digital camera: receiving the image groupinformation specifying one or plurality of image groups from its owncomputer in the possession of the user who possesses this digitalcamera, and transmitting to its own computer an image file, which hasbeen obtained by image sensing using the digital camera, and image groupinformation in which the image file is to be included; and said owncomputer, which has received the image file and the image groupinformation, storing the received image file in linkage with an imagefolder corresponding to the received image group information; indownload processing for downloading an image file, said digital camera:receiving from said center server the image group information specifyingone or plurality of image groups to which the user possessing thisdigital camera belongs, accepting selection of any one item of imagegroup information from among the items of image group informationreceived, and transmitting the image group information selected to saidcenter server; and said center server transmitting, to said digitalcamera, access information for accessing other computers possessed byone or a plurality of other users who belong to the image groupspecified by the image group information received; the digital camerathat has received this access information transmitting the selectedimage group information to another computer based upon the accessinformation received; and the other computer that has received the imagegroup information from the digital camera transmitting an image file,which has been linked to an image folder corresponding to the imagegroup information received, to said digital camera.
 2. A digital cameraused in an image file sharing system constituted by said digital cameraand a computer possessed by each of a plurality of users, and a centerserver capable of data communication with the digital cameras andcomputers via a network, wherein said center server has a managementinformation storage device for storing, on a per-user basis, managementinformation that includes image group information specifying one or aplurality of image groups to which the user belongs and accessinformation for accessing each computer, and each computer has an imagegroup information storage device for storing image group informationspecifying one or a plurality of image groups to which a user possessingsaid computer belongs, and an image file storage device for storing animage file, which is transmitted from a digital camera, in linkage withan image folder corresponding to image group information transmittedfrom the digital camera together with the image file, said digitalcamera comprising: first image group information receiving means forreceiving the image group information specifying one or plurality ofimage groups from its own computer in the possession of the user whopossesses this digital camera; image file transmitting means fortransmitting an image file, which has been obtained by image sensingusing the digital camera, and image group information in which the imagefile is to be included, to its own computer; second image groupinformation receiving means for receiving from said center server theimage group information specifying one or plurality of image groups towhich the user possessing this digital camera belongs; image groupinformation selecting means for accepting selection of any one item ofimage group information from among the items of image group informationreceived; image group information transmitting means for transmittingthe image group information selected to said center server; accessinformation receiving means for receiving access information, which istransmitted from said center server, for accessing other computerspossessed by one or a plurality of other users who belong to the imagegroup specified by the image group information received; accessing meansfor transmitting the selected image group information to anothercomputer based upon the access information received; and image filereceiving means for receiving an image file, which has been linked to animage folder corresponding to the image group information, transmittedfrom another computer that has received the image group information fromthe digital camera.
 3. The digital camera according to claim 2, furthercomprising image group name display means for displaying an image groupname on a display screen of a display unit based upon image groupinformation specifying one or a plurality of image groups received bysaid first image group information receiving means and said second imagegroup information receiving means.
 4. The digital camera according toclaim 2, further comprising: a removable memory card; and memory cardcontrol means for recording an image file, which has been received bysaid image file receiving means, on said memory card.
 5. The digitalcamera according to claim 2, wherein the image file includes originalimage data and thumbnail image data, and said digital camera furthercomprises: thumbnail image data receiving means for receiving thumbnailimage data, which is transmitted from another user computer that hasreceived the image group information transmitted by said accessingmeans, contained in an image file that has been linked to an imagefolder corresponding to an image group identified by the image groupinformation; thumbnail image display means for displaying a thumbnailimage represented by the thumbnail image data; desired-image selectingmeans for selecting an image, which is desired to be downloaded, fromamong thumbnail images display by said thumbnail image display means;and download request transmitting means for transmitting a downloadrequest to another computer having the image selected; said image filereceiving means receiving an image file, which is desired to bedownloaded, transmitted from another computer that has received adownload request.
 6. In an image file sharing system constituted bydigital cameras and computers possessed by each of a plurality of usersand a center server capable of data communication with the digitalcameras and computers via a network, said center server comprises: imagegroup information/access information storage means for storing, on aper-user basis, image group information specifying one or a plurality ofimage groups to which the user belongs and access information foraccessing each of the computers; image group information transmittingmeans for transmitting to said digital camera the image groupinformation specifying one or plurality of image groups to which theuser possessing the digital camera belongs; image group informationreceiving means for receiving any one item of image group informationtransmitted from a digital camera; and access information transmittingmeans for transmitting to said digital camera access information foraccessing other computers possessed by one or a plurality of other userswho belong to the image group specified by the image group informationreceived.
 7. A digital camera used in an image file sharing/printingsystem constituted by said digital camera and a computer possessed byeach of a plurality of users, a center server capable of datacommunication with the digital cameras and computers via a network, anda printer capable of data communication with the digital cameras andcomputers via a network, wherein said center server has a managementinformation storage device for storing, on a per-user basis, managementinformation that includes image group information specifying one or aplurality of image groups to which the user belongs and accessinformation for accessing each computer, each computer has an image filestorage device for storing an image file, which includes thumbnail imagedata and original image data, in linkage with an image foldercorresponding to one or a plurality of image groups to which a userpossessing the computer belongs, and said printer has a communicationunit which, on the basis of image specifying information and computerspecifying information transmitted from said digital camera, accesses acomputer specified by the computer specifying information and receivesan image file specified by the image specifying information transmittedfrom said computer, said digital camera comprising: image groupinformation receiving means for receiving, from said center server, theimage group information specifying one or plurality of image groups towhich the user possessing said digital camera belongs; image groupinformation selecting means for accepting selection of any one item ofimage group information from among the items of image group informationreceived; image group information transmitting means for transmittingthe image group information selected to said center server; accessinformation receiving means for receiving access information, which istransmitted from said center server, for accessing a computer orcomputers possessed by one or a plurality of other users who belong tothe image group specified by the image group information selected;accessing means for transmitting the selected image group information tosaid one or plurality of computers based upon the access informationreceived; thumbnail image data receiving means for receiving thumbnailimage data, which is transmitted from a computer that has received theimage group information from the digital camera, contained in an imagefile that has been linked to an image folder corresponding to an imagegroup identified by the image group information; display means fordisplaying a thumbnail image represented by the thumbnail image data;selecting means for selecting an image, which is desired to be printed,from among thumbnail images displayed by said display means; andspecifying information transmitting means for transmitting, to saidprinter, information specifying an image to be printed selected by saidselecting means and information specifying a computer having an imagefile that represents the image to be printed.
 8. The digital cameraaccording to claim 7, further comprising print-number designating meansfor designating number of prints of an image to be printed; wherein saidspecifying information transmitting means further transmits informationrepresenting number of prints.
 9. A method of controlling a digitalcamera used in an image file sharing/printing system constituted by saiddigital camera and a computer possessed by each of a plurality of users,a center server capable of data communication with the digital camerasand computers via a network, and a printer capable of data communicationwith the digital cameras and computers via a network, wherein saidcenter server has a management information storage device for storing,on a per-user basis, management information that includes image groupinformation specifying one or a plurality of image groups to which theuser belongs and access information for accessing each computer, eachcomputer has an image file storage device for storing an image file,which includes thumbnail image data and original image data, in linkagewith an image folder corresponding to one or a plurality of image groupsto which a user possessing the computer belongs, and said printer has acommunication unit which, on the basis of image specifying informationand computer specifying information transmitted from said digitalcamera, accesses a computer specified by the computer specifyinginformation and receives an image file specified by the image specifyinginformation transmitted from said computer, said method comprising thesteps of: receiving, from said center server, the image groupinformation specifying one or plurality of image groups to which theuser possessing said digital camera belongs; accepting selection of anyone item of image group information from among the items of image groupinformation received; transmitting the image group information selectedto said center server; receiving access information, which istransmitted from said center server, for accessing a computer orcomputers possessed by one or a plurality of other users who belong tothe image group specified by the image group information selected;transmitting the selected image group information to said one orplurality of computers based upon the access information received;receiving thumbnail image data, which is transmitted from a computerthat has received the image group information from the digital camera,contained in an image file that has been linked to an image foldercorresponding to an image group identified by the image groupinformation; displaying a thumbnail image represented by the thumbnailimage data received; selecting an image, which is desired to be printed,from among thumbnail images displayed; and transmitting, to saidprinter, information specifying a selected image to be printed andinformation specifying a computer having an image file that representsthe image to be printed.
 10. The method according to claim 9, furthercomprising the steps of: accepting designation of number of prints of animage to be printed; and transmitting information representing number ofprints to said printer.